In the related art, mechanical strength indicators such as elongation at break Eb and tensile strength at break TSb are used as performance evaluation indicators for rubber members such as conveyor belts.
For example, when a conveyed article is loaded on a conveyor belt, the conveyed article may impact strongly against a cover rubber covering a core body, causing cut damage to the surface of the cover rubber. To reduce this cut damage, rubber with high mechanical strength (elongation at break Eb and tensile strength at break TSb) has been developed.
A known method of evaluating this type of rubber material includes a DIN abrasion test in which a test piece made of a rubber material is pressed against a cylindrical member with an abrasive cloth wound on the outer circumferential surface, the cylindrical member is rotated a predetermined number of times, and the wear amount of the test piece is measured.
Furthermore, a known technique for evaluating the durability of a rubber material for a conveyor belt, a method has been proposed in which the durability of a rubber material is evaluated on the basis of how much the weight of a test piece made from a rubber material for a conveyor belt was reduced by abrasive blasting the test piece for a predetermined period of time (see Patent Document 1 below). As described in Patent Document 1, a large impact force is applied to the surface of the test piece when the granular matter collides with the surface of the test piece, and the surface of the test piece is abraded by the impact force being applied multiple times. In other words, the test piece can be subjected to wear similar to the wear actually experienced by a conveyor belt, making it possible to reproduce the durability of an actual conveyor belt.